1. Field of the Invention
This invention relates to a tubular metal ball bat, such as a baseball bat or a softball bat, which includes a tubular barrel having a hitting zone and an end cap at the distal end, a handle at the proximal end and a pressurized bladder inserted into the tubular barrel in the area of the hitting zone. This invention also relates to the method of inserting and anchoring the pressurized bladder in the hitting zone.
2. Description of the Prior Art
Hollow metal bats of aluminum or similar material have been developed and have been in use for many years when playing baseball, softball and the like. Improvements and developments have been made in the construction of hollow metal bats since their introduction. Such improvements and developments are disclosed in earlier U.S. Pat. Nos. 5,393,055, 5,421,572 and 5,494,280. In addition, the distal end of such bats has traditionally been reinforced by various closure caps and constructions. Efforts have also been made to cushion and reinforce the bat by completely filling the interior of the bat with a polyurethene foam material as disclosed in U.S. Pat. No. 4,682,773. Additionally, efforts have been made to improve the characteristics of a metal bat by introducing air under pressure into the entire interior of a hollow metal bat as disclosed in U.S. Pat. No. RE 31,811. The following U.S. patents also illustrate various developments relating to this field of endeavor:
______________________________________ 1,831,255 3,479,030 5,364,095 2,227,817 3,963,239 5,415,398 3,233,727 4,744,136 5,511,777 ______________________________________
The foregoing patents disclose bats filled with foam to increase the strength of the bat as well as bats of hollow metal construction or other hollow metal devices that have been otherwise modified in order to improve their operational characteristics. However, the prior art does not disclose the concept of including a pressurized bladder or bladders in the area of the hitting zone of a hollow metal bat with the bladder or bladders being accurately positioned and retained in place in the hitting zone area.